The present invention relates to electrical and optical materials, and to organic electro-conductive thin films exhibiting electro-conductivity and non-linear optical effects and the process for production thereof.
The following is the explanation about conventional techniques, taking the case of polyacetylene.
Because polymers of acetylene derivatives having .pi. electron conjugation system exhibit electro-conductivity and non-linear optical effects, the polymers are being widely investigated as electrical and optical functional materials.
As a conventional polyacetylene production method, a polymerization method using a catalyst, called "Shirakawa method," has been well-known.
On the other hand, amphoteric acetylene derivatives having both of hydrophilic group(s) and hydrohobic group(s) can form monomolecular films, which are ultrathin films in angstrom order, and its built-up films, using the Langmuir-Blodgett technique. Therefore, polyacetylene is well investigated with Langmuir-Blodgett technique.
Next, the issues to be solved by the invention are explained, taking the case of polyacetylene. With conventional polyacetylene production methods using catalysts, represented by Shirakawa method, the forming direction of polyacetylene molecules cannot be controlled. Therefore, stretching methods, liquid crystal magnetic field methods or other technique are attempted. As the stretching methods are a dynamic orientation control method and the technique gives polyacetylene some tension, the technique is not preferable. The liquid crystal magnetic field technique utilizes the orientation condition of liquid crystal; however, it is impossible to allow all molecules to orient. Moreover, the technique is limited in the kind of material on which it can be used. In addition, with conventional techniques, the chain length of polymer is short and hyperconjugated molecules cannot be formed. Therefore, to date, there has been little success using either the molecule orientation control techniques or long chain polymer forming techniques.